The present disclosure relates generally to communication networks, and more particularly to Layer 2 Multipath (L2MP) networks.
Layer 2 MultiPath architectures include Data Center Ethernet (DCE) and TRansparent Interconnection of Lots of Links (TRILL). Data Center Ethernet is a collection of Ethernet extensions which provide enhancements to Classical Ethernet (CE) targeted for specific use in the data center. TRILL is an IETF (Internet Engineering Task Force) protocol implemented by devices referred to as Routing Bridges or RBridges (see, for example, RBridges: Base Protocol Specification, draft-ietf-trill-RBridge-protocol-14.txt, R. Perlman et al., Oct. 26, 2009). TRILL introduces new data and control planes for Ethernet networks.
In both DCE and TRILL deployments, the cost of a link is proportional to its bandwidth and is configurable on a per-link basis. This information can be communicated to peers of a switch using, for example, IS-IS (Intermediate System to Intermediate System). Limiting assignment of a link cost to a per-link basis in L2MP networks results in a number of drawbacks, including under utilization of links and complications for technologies such as Virtual Port Channel (vPC) at a junction between DCE and CE networks.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.